Article 763 Bis Federal Labor Law

With respect to the incidents promoted in the Ordinary Individual Proceeding, the incidents shall be substantiated and resolved at the preliminary hearing, hearing the parties, without suspension of the procedure, except for the incident of nullity, which must be promoted within the three days following the day on which the irregular act is known, and before judgment is issued. In this case, the judge shall set a day and hour for the holding of the incidental hearing, which shall take place within the following twenty-four hours, at which documentary, instrumental and presumptive evidence may be offered and produced so that the incident is immediately resolved, and the procedure shall continue.

Anyone who promotes an incident that is notoriously improper shall be fined up to 100 times the Measurement and Updating Unit (Unidad de Medida y Actualización).